This invention relates to grease trap assemblies provided in waste water drain line systems, and more particularly to such grease trap assemblies having automatic, powered skimmer arrangements for skimming and removing grease and oils from the wastewater passing through the grease trap assembly prior to exiting through an outlet into the municiple sewer system serving the facility. Such grease trap assemblies are used in connection with commercial food preparation sinks, rinse sinks and dishwashing and utensil washing facilities and such in restaurants, fast food outlets, hospitals, hotels and other large kitchen facilities that produce grease and oil-laden wastewater in order to reduce the amount of grease, cooking oil and other contaminants that are introduced into the municipal sewer system and treatment facilities serving the area.
These grease trap assemblies are well known in the industry and range in complexity from structurally simple units that require periodic manual skimming by facility personnel to rather complex structural arrangements that provide for automatic skimming and pump discharge of skimmed grease and oil into external containers positioned adjacent the side wall of the trap assembly. The simple forms of traps in essence simply provide an enclosed, hollow box or settling tank structure having a kitchen wastewater inlet at one end and an outlet at the opposite end for connection to a sewer line, baffle plates typically being arranged within the cavity to interrupt direct flow-through of wastewater between the inlet and outlet, and defining a separation area between the baffles in which grease and oil may naturally float to the surface of the wastewater contained within the box. Periodically as needed, an employee must remove the top cover of the box and manually skim the grease and oil that has accumulated at the surface of the wastewater. This is an extremely unpleasant and time consuming task, made worse as is well known by the pungent and foul odors that are inherent in the skimmed materials.
Grease trap assemblies having automatic skimmer arrangements contained within the trap box have also been provided heretofore, and typically utilize rotating skimmer discs connected to an external drive means arranged to cause continuous rotation of the discs within the trap housing. The discs are cleaned by wiper blades arranged to direct grease and oil to a pump arrangement for pump discharge or by gravity flow into a holding container disposed alongside or vertically below the trap apparatus, such, as taught by U.S. Pat. Nos. 5,133,881, 4,268,396 and 4,051,024. These power skimmer arrangements all provide structurally complex rotating disc-type mechanical assemblies contained substantially entirely within the body housing of the grease traps and therefore are arranged, and structurally capable only of discharging skimmed grease and oils to the side of the grease trap tank adjacent to and alongside the external periphery of the tank. This requires additional floor space in the kitchen facility beyond that required by the grease trap tank itself, and completely prevents installation of these types of assemblies in in-floor situations. Moreover, because the skimming disc apparatus and related mechanical and often electrical structure of the grease skimming and removal apparatus of these patent teachings are contained and mounted within the hollow confines of the wastewater holding tank of the grease trap assemblies, routine and periodic inspection and maintenance of the assemblies requires access into the tank which is designed to maintain a predetermined level of grease-laden wastewater therein, making such operations extremely unpleasant and difficult to perform. Also the mechanical structures, since they occupy space within the interior confines of the grease trap tanks, obstruct inspection of the bottom of the tank for identifying and cleaning of the bottom of the tank of accumulated solids, etc. that invariably settle and build up over time. Further, since the mechanical and electrical components of the skimmer apparatus are contained in either submerged or close proximity to the water retained in the grease trap tank, these parts must be provided in a more expensive form capable of withstanding the hot and humid environment in which they must operate.
The present invention provides a skimming apparatus which is well adapted for inclusion in original manufacture of a complete grease trap assembly, but the invention is also particulary well adapted for retrofitting and upgrading existing, already installed and in use manual skimming trap assemblies into automatic skimmer condition as will become readily apparent. No other automatic grease removal skimmer apparatus has been provided heretofore that is arranged for and structurally capable of reasonably retrofitting existing, already installed grease trap assemblies, and it has been discovered that there is a great need and desire in the marketplace for such an apparatus.